• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.341-344
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• 2000

Several new via structures in printed circuit boards are proposed, fabricated and characterized in RF regime. The new structure with a larger inductance component in the bottom layer shows 3㏈ improvement over the conventional structure. The ADS simulation with model parameters extracted from 3D fie]d solver matches with the characterization of these vias

• Journal of Korean Association for Spatial Structures
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• v.19 no.4
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• pp.85-94
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• 2019

Then 3D printing is used practically at construction sites, there is a serious lack of studies on the conflict with construction-related laws and expected operational problems. Accordingly, the purpose of this study is to present obstacles and directions for improvement in construction-related laws (Building Act, Construction Technology Promotion Act, Housing Act, Construction Machinery Management Act, etc.) for practical operation of 3D printing. The important results are as follows. Amending existing construction-related laws for 3D printing is irrational and inefficient in terms of structure and material. This study proposed a method of satisfying performance required by laws or standards based on the performance design method presented in existing laws and systems through structure and material performance certification procedure. In addition, inclusion of 3D printing equipment in the Construction Machinery Management Act results in various restrictions such as equipment inspection and certification of machine parts. As such restrictions can block vitalization of 3D printing, a long-term and step-wise approach was suggested.

• Journal of Institute of Convergence Technology
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• v.10 no.1
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• pp.7-12
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• 2020

We describe a efficient surface reconstruction method that reconstructs a 3D manifold polygonal mesh approximately passing through a set of 3D oriented points. Our algorithm includes 3D convex hull, octree data structure, signed distance function (SDF), and marching cubes. The 3D convex hull provides us with a fast computation of SDF, octree structure allows us to compute a minimal distance for SDF, and marching cubes lead to iso-surface generation with SDF. Our approach gives us flexibility in the choice of the resolution of the reconstructed surface, and it also enables to use on low-level PCs with minimal peak memory usage. Experimenting with publicly available scan data shows that we can reconstruct a polygonal mesh from point cloud of sizes varying from 10,000 ~ 1,000,000 in about 1~60 seconds.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.585-592
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• 2000

Primary purpose of the system developed in this study is 3-D seismic data processing system for subsurface structure imaging and this system is developed in PC based on Linux for lower-cost computer. Basic data processing modules are originated from SU (Seismic Unix) which is widely used in 2-D seismic data processing and auxilious modules are developed for 3-D data processing. The system which is constructed by using these data processing modules is designed to GUI (Graphic User Interface) in order that one can easily control and for this purpose, GTK (Gimp Tool KiT) conventionally adapted in producing Linux application.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.5
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• pp.688-693
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• 1999

This paper presents a very simple coupled line structure for MMIC which uses stacked microstrip line and does not employ any dielectric process step. For the analysis and optimization of these coupled line structure, HP-Momentum was used. The measured performance of 3 dB coupler shows 23 to 45 GHz broadband characteristics. Additionally, a balanced 2-stage Ka-Band power amplifier which uses the proposed 3 dB coupler, was also fabricated.

• Journal of Integrative Natural Science
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• v.5 no.1
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• pp.1-5
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• 2012

Quantitative structure-activity relationship (QSAR) methodologies have been applied for many years, to correlate the relationship between physicochemical properties of chemical substances and their biological activities to generate a statistical model for prediction of the activities of new chemical entities. The basic principle behind the QSAR models is that, how structural variation is responsible for the difference in biological activities of the compounds. 3D-QSAR has emerged as a natural extension to the classical Hansch and Free-Wilson approaches, which develops the 3D properties of the ligands to predict their biological activities using various chemometric techniques (PLS, G/PLS, ANN etc). It has served as a valuable predictive tool in the design of pharmaceuticals and agrochemicals. This review seeks to provide different 3D-QSAR approaches involved in drug designing process to develop structure-activity relationships and also discussed the fundamental limitations, as well as those that might be overcome with the improved methodologies.

• Journal of the Korean Society of Clothing and Textiles
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• v.42 no.4
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• pp.612-625
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• 2018

This study designed 16 kinds of basic structure and 4 kinds of modified structure for impact protection pads with a spacer fabric shape. The pad is a structure in which hexagonal three-dimensional units, composed of a surface layer and a spacer layer, are interconnected. Designed pads were printed with flexible $NinjaFlex^{(R)}$ materials using a FDM 3D printer. The printed pads were evaluated for impact protection performance, compression properties and sensory properties. The evaluation of the impact protection performance indicated that basic structures better than CR foam material at 20cm height were DV1.5, DX1.5, DX1.0, DV1.0 and HV1.5. The evaluation of the compression properties for the five types, with good results in the impact protection performance, indicated that DV1.0, DX1.0, DV1.5, HV1.5 and DX1.5 showed good results, respectively. The sensory evaluation of DV1.0, DX1.0, and DV1.5, which with good results when considering both the impact protection performance and the compression performance, showed that DV1.0 were the best for surface, flexibility, compression and weight. Therefore, DV1.0 is shown to be the best structure for protection pads.

• Journal of IKEEE
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• v.25 no.4
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• pp.774-777
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• 2021

In this paper, we analyzed the gate controllability of 3D NAND Flash Memory with Charge Trap Flash using Ferroelectric (CTF-F) structure. HfO₂, a ferroelectric material, has a high-k characteristic besides polarization. Due to these characteristics, gate controllability is increased in CTF-F structure and on/off current characteristics are improved in Bit Line(BL). As a result of the simulation, in the CTF-F structure, the channel length of String Select Line(SSL) and Ground Select Line(GSL) was 100 nm, which was reduced by 33% compared to the conventional CTF structure, but almost the same off-current characteristics were confirmed. In addition, it was confirmed that the inversion layer was formed stronger in the channel during the program operation, and the current through the BL was increased by about 2 times.

• The Journal of the Korea Contents Association
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• v.10 no.4
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• pp.66-75
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• 2010

In Augmented Reality, it needs restoration and tracking of a real-time scene structure for the augmented 3D model from input video or images. Most of the previous approaches construct accurate 3D models in advance and try to fit them in real-time. However, it is difficult to measure 3D model accurately and requires long pre-processing time to construct exact 3D model specifically. In this research, we suggest a real-time scene structure analysis method for the wide indoor mobile augmented reality, using only generic models without exact pre-constructed models. Our approach reduces cost and time by removing exact modeling process and demonstrates the method for restoration and tracking of the indoor repetitive scene structure such as corridors and stairways in different scales and details.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.816-821
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• 2009

In this paper, I would like to talk about a step by step detailed information browsing which is founded on hierarchical structure for offering suitable information about the mass 3D data of a national treasure building to user as a standard of the visual distance. A step by step detailed information of the national treasure building of gigantic proportions offers a process of detailed information browsing which decided suitable hierarchical structure as considering of the preprocessing procedure which produces hierarchical structure and a visual distance of user. In the preprocessing procedure, 3D data is divided and controlled by optimized spacial structures. The relevance connection between the inner spacial surface is then examined and reconfigured in order to prevent holes or distortions. Finally, relative information data is created. In detailed information browsing, by examining the visual distance between model and user, then by browsing proper step of data, suitable level model data can be provided to the users in accordance with the position of observation.